The following relates generally to wireless communication, and more specifically to spatial listen before talk by precoded request to send and clear to send via whitening.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system, or a New Radio (NR) system). A wireless multiple-access communications system may include a number of base stations or access network nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
In some wireless communications systems, a medium reservation protocol may be used to allow a wireless device to reserve the wireless channel such that the wireless device can transmit without interference from another device. One such medium reservation protocol may include the exchange of request to send (RTS) signals and clear to send (CTS) signals. The wireless device that has data ready to transmit may first transmit a RTS signal to the intended recipient. The RTS signal may include a duration field that indicates the length of time for which the wireless device wants to reserve the medium. All devices that hear the RTS signal may then refrain from transmitting for that length of time by setting their network allocation vectors (NAVs). The intended recipient may respond with a CTS signal that includes a duration field. Any devices that hear the CTS signal but did not hear the RTS signal may also set their NAVs and thereby refrain from interfering with reception at the intended recipient. The transmitting device may transmit data to the intended recipient upon receiving the CTS signal.